Automatic Injection Device With Variable Dosing

ABSTRACT

A medication delivery device, for use with a container having a distal end and a needle being placed at the distal end of the container, including: a push rod which is movable with respect to at least a portion of the container; a resilient member configured to bias the push rod to move toward the distal end of the container; a releasable restraining means configured to releasably restrain the push rod in a locked state against the biasing of the resilient member; a means to adjust amount of movement of the push rod with respect to the container in order to deliver a predetermined dose of medication; and an activation means configured to release the releasable means. The means to adjust amount of movement of the push rod with respect to the container is bi-directional. The device can accommodate containers of different size or shape.

TECHNICAL FIELD

The invention relates to an automatic medication delivery device fordelivering liquid medications.

BACKGROUND OF THE INVENTION

As biologic drugs increase in popularity, parenteral delivery devicesare expected to be widely used. Injection drug delivery devices, suchlike the automatic injection devices, can ease medicationpreparation/administration and reduce needle injury, which results inimproved patient convenience and compliance. Due to the advantagesmentioned above, more patients and healthcare professionals preferautomatic injection devices to the traditional manual syringes. However,current automatic injection devices are mostly designed for fix dosedelivery. This limits the use of parenteral drugs that require variabledosing for different patient population as well as different therapeutictreatments. Although there are injection devices, such as insulin pen,can be used to inject variable doses, those devices often don't haveautomatic injection function and/or cannot be used to inject relativelylarge volume, for example, more than 0.5 mL for a single injection.Moreover, the dose setting for insulin pen type of injector is oftenunidirectional, which is very inconvenient for users. As an example, the“Instructions for Use” of insulin injection device Autopen® developed byOwen Mumford Ltd requires users not to dial back dose. If at any timethe dose has been over dialed using the Autopen® device, it isrecommended that the incorrect dose is fully expelled into air and therequired dose is redialed. Meantime, while US patent application US2010/0010454 discloses an automatic injection device for deliveringvariable dose, the disclosed device in US patent application US2010/0010454 doesn't disclose a mechanism to prevent the radial rotationand back-threading of the push rod (named as plunger in the US patentapplication US 2010/0010454) after the injection device is activated.Consequently, the target delivery dose cannot be achieved by using thedevice embodiment disclosed in US patent application US 2010/0010454.Therefore, injection devices based on a novel design principal are inneed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an automaticmedication delivery device. This invention is to overcome one or more ofthe disadvantages of the prior art.

It is an advantage of the present invention that the automaticmedication delivery device embodiments here can be used for deliveringvariable dose and provide option for users to adjust injection dose upto entire content of the medication container in the device embodiments.

It is an advantage of the present invention that the automaticmedication delivery device embodiments here have automatic injectionfunction, assisted by mechanical spring, so that the injection deviceembodiments are ergonomic to use for delivering high volume, highlyviscous medications.

It is an advantage of the present invention that the injection volumecan be pre-determined and the pre-determined injection volume will notchange during the entire injection process.

It is an advantage of the present invention that, in at least oneembodiment, the dose setting is bidirectional. By using the embodimentsin the present invention, user can simply either increase dose ordecrease dose by moving the dose setting mechanism in either direction,in the same manner, until the correct dose is selected, beforeinjection.

It is an advantage of the present invention that, in at least oneembodiment, the automatic medication delivery device works withpre-filled medication container.

It is an advantage of the present invention that, in at least oneembodiment, the maximum automatic dose can be set by a medicalprofessional or patient to prevent over dose.

It is an advantage of the present invention that, in at least oneembodiment, the injection dose can be pre-set by a pharmacist or medicalprofessional, and patient will not be able to change the pre-set dosethereafter.

It is a further advantage of the present invention that, in at least oneembodiment, the dose setting mechanism can be customized for differentmedications and/or different patients.

Due to the simplicity of its operation and its unique functionalfeatures, the medication delivery device embodiments of this inventionare well suited for use by a wide range of patients including childrenand those with permanent or temporary disabilities.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are schematic and simplified for clarity, and they just showdetails, which are essential to the understanding of the invention,while other details are left out. Throughout, the same referencenumerals are used for identical or corresponding parts.

FIG. 1 is a perspective view of an exemplary automatic medicationdelivery device assembly according to the invention.

FIG. 2 shows cross-sectional views of the exemplary automatic medicationdelivery device assembly, before injection, with different dosesettings, according to the invention.

FIG. 3 shows cross-sectional views of the exemplary automatic medicationdelivery device assembly, after injection, with different dose settings,according to the invention.

FIG. 4-6 are detailed views showing engagements between components ofthe exemplary automatic medication delivery device assembly according tothe invention.

FIG. 7 shows cross-sectional view of another configuration of theexemplary automatic medication delivery device assembly according to theinvention.

FIG. 8 is a perspective view of the first alternative automaticmedication delivery device assembly according to the invention.

FIG. 9 is a cross-sectional view of the first alternative automaticmedication delivery device assembly according to the invention.

FIG. 10 is an exploded view of the first alternative automaticmedication delivery device assembly according to the invention.

FIG. 11 shows cross-sectional views of the first alternative automaticmedication delivery device assembly, before injection, with differentdose settings, according to the invention.

FIG. 12 shows cross-sectional views of the first alternative automaticmedication delivery device assembly, after injection, with differentdose settings, according to the invention.

FIG. 13-20 show engagements between components of the first alternativeautomatic medication delivery device assembly according to theinvention.

FIG. 21 is a perspective view of the second alternative automaticmedication delivery device assembly according to the invention.

FIG. 22 shows cross-sectional views of the second automatic medicationdelivery device assembly, before injection, with different dosesettings, according to the invention.

FIG. 23 shows cross-sectional views of the second automatic medicationdelivery device assembly, after injection, with different dose settings,according to the invention.

FIG. 24-26 show engagements between components of the second alternativeautomatic medication delivery device assembly according to theinvention.

FIG. 27 is a perspective view of the third alternative automaticmedication delivery device assembly according to the invention.

FIG. 28 is an exploded view of the third alternative automaticmedication delivery device assembly according to the invention.

FIG. 29 is a perspective view of the fourth alternative automaticmedication delivery device assembly according to the invention.

FIG. 30 is a perspective view of a component used in the fourthalternative automatic medication delivery device assembly according tothe invention.

FIG. 31 shows cross-sectional views of the fourth alternative automaticmedication delivery device assembly, before injection, with differentdose settings, according to the invention.

FIG. 32 shows cross-sectional views of the fourth alternative automaticmedication delivery device assembly, after injection, with differentdose settings, according to the invention.

FIG. 33 is a perspective view of a component used in the fourthalternative automatic medication delivery device assembly according tothe invention.

FIGS. 34 and 34A show engagements between components of the fourthalternative automatic medication delivery device assembly according tothe invention.

FIG. 35 is a perspective view of the fifth alternative automaticmedication delivery device assembly according to the invention.

FIG. 36 is a perspective view of the fifth alternative automaticmedication delivery device assembly used together with a medicationcontaining vial, according to the invention.

FIG. 37-37C show steps of using the fifth alternative automaticmedication delivery device assembly according to the invention.

FIGS. 38 and 39 show engagements between components of the fifthalternative automatic medication delivery device assembly according tothe invention.

FIG. 40 is a perspective view of the sixth alternative automaticmedication delivery device assembly according to the invention.

FIG. 41 is a cross-sectional view of the sixth alternative automaticmedication delivery device assembly according to the invention.

FIGS. 42 and 43 show perspective views of the seventh alternativeautomatic medication delivery device assembly, before and afterinjection, according to the invention.

FIG. 44 shows cross-sectional views of the seventh alternative automaticmedication delivery device assembly, before injection, with differentdose settings, according to the invention.

FIG. 45 shows cross-sectional views of the seventh alternative automaticmedication delivery device assembly, after injection, with differentdose settings, according to the invention.

FIG. 46-47 show perspective views of another configuration of theseventh alternative automatic medication delivery device assemblyaccording to the invention.

FIG. 48 shows engagements between components of the seventh alternativeautomatic medication delivery device assembly according to theinvention.

FIG. 49 shows perspective view of the eighth alternative automaticmedication delivery device assembly according to the invention.

FIG. 50 shows cross-sectional views of the eighth alternative automaticmedication delivery device assembly according to the invention.

FIGS. 51 and 52 show perspective views of the ninth alternativeautomatic medication delivery device assembly according to theinvention.

FIG. 53-53B show steps of using the ninth alternative automaticmedication delivery device assembly according to the invention.

FIGS. 54 and 55 show engagements between components of the ninthalternative automatic medication delivery device assembly according tothe invention.

FIGS. 56 and 57 show perspective views of the tenth alternativeautomatic medication delivery device assembly with different dosesettings according to the invention.

FIG. 58 shows cross-sectional view of the tenth alternative automaticmedication delivery device assembly according to the invention.

FIG. 59 shows front views of the tenth alternative automatic medicationdelivery device assembly, before and after injection, according to theinvention.

FIG. 60 shows perspective view of another configuration of the tenthalternative automatic medication delivery device assembly according tothe invention.

Corresponding parts are marked with the same reference symbols in allfigures.

DETAILED DESCRIPTION THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus, are not limitiveof the present invention, and wherein:

The apparatus and methods presented herein can be used for deliveringany of a variety suitable therapeutic agents or substances, such as adrug, into a patient. Initially it may be convenient to define that, theterm “distal end” is meant to refer to the end of the automaticmedication delivery device assembly inserted into the patient, whereasthe term “proximal end” is meant to refer to the end opposite to the“distal end” along the longitudinal axis of the device body. The words“upper”, “lower”, “right” and “left” designate directions in thedrawings to which reference is made. The Words “inward” and “outward”refer to directions toward and away from, respectively,

FIGS. 1-7 illustrate the construction and function mechanism of anexemplary automatic medication delivery device assembly 10 according tothe invention.

In this exemplary automatic medication delivery device assembly 10, apre-filled syringe 101, as medication container, can be made of eitherglass or plastic materials. A push cap 104 is used to activate anautomatic injection. The push cap 104 is engaged with a dialing cylinder103, through a track 103 a on the dialing cylinder 103. This engagementprevents accidental activation of the device before use. A dose settingwindow 102 a being defined on a scale cylinder 102. During use, thedialing cylinder 103 is rotated to set the injection dose. Withreference to FIG. 2, user sets the location of a stopping ring 108 inorder to get the different injection doses. Meantime, before injection,the automatic medication delivery device assembly 10 is shown with apush rod 105 in a locked state, against biasing force of a drivingspring 107, by a releasable latch mechanism formed between hook feature105 a on the push rod 105 and the dialing cylinder 103. The pre-filledsyringe 101 is assembled together with the scale cylinder 102 through aflange feature 101 b being defined on the pre-filled syringe 101. Theliquid medication in the pre-filled syringe 101 is sealed by a piston106 and an elastomeric needle shield 101 a. With reference to FIG. 3,before injection, the needle shield 101 a is removed and a needle 101 cis exposed. During injection, the push cap 104 is pushed toward to thedistal end of the device, a distally-directed tapered actuation feature104 a on the push cap 104 releases the releasable latch mechanism formedbetween hook feature 105 a on the push rod 105 and the dialing cylinder103. The push rod 105 is released and the driving spring 107 drives thestopping ring 108 together with the push rod 105 to move toward thedistal end of the automatic medication delivery device 10. The piston106 is pushed downward. Consequently, liquid medication in thepre-filled syringe 101 is injected from the device into patient's body.The stopping ring 108 stops at a landing feature 102 b on the scalecylinder 102. The pre-set dose is delivered accordingly. FIG. 4 showsthe engagements between the push rod 105 and the dialing cylinder 103. Arectangular shape channel feature 103 b on the dialing cylinder 103engages with flat surfaces 105 b on the push rod 105. When user rotatesthe dialing cylinder 103, the push rod 105 rotates accordingly. Therectangular shape channel feature 103 b further provides landing surfacefor the releasable hook feature 105 a on the push rod 105. FIG. 5 showsengagements among the push rod 105, the stopping ring 108 and the scalecylinder 102. During the dose setting, user rotates the dialing cylinder103 relative to the scale cylinder 102. Because of a thread feature 105c on the push rod 105, when the push rod 105 rotates, the stopping ring108 moves up and down along axial of the device, through the threadengagement between the push rod 105 and stopping ring 108. The locationof the stopping ring 108 can be viewed through viewing window 102 a onthe scale cylinder 102. Due to the constrain between groove feature 108a on the stopping ring 108 and rail feature 102 c on the scale cylinder102, the stopping ring 108 can only moves axially, but not radiallyalong the push rod 105 during dose setting and during injection. FIG. 6shows the engagement between the dialing cylinder 103 and the scalecylinder 102. In operation steps other than the dose setting step, thedialing cylinder 103 is always locked with the scale cylinder 102together, through a tooth engagement between 103 c on the dialingcylinder 103 and 102 d on the scale cylinder 102, or some othermechanism which allows the components to be connected and disconnectedfrom each other. This tooth-type lock engagement prevents free rotationof the dialing cylinder 103 and restrain the radial movement andback-threading of the push rod 105 during the entire injection process.During the dose setting step, user pushes the dialing cylinder 103distally relative to the scale cylinder 102. Then, the lockingengagement between 103 c and 102 d is disabled and the dialing cylinder103 can be rotated relatively to the scale cylinder 102. After the dosesetting, when there is absent of pushing force toward distal end of theautomatic medication delivery device 10, the dialing cylinder 103 isbiased proximally and re-engaged with the scale cylinder 102, due to theresilient force generated by the piston 106 or a separation spring 109(shown on FIG. 7).

FIGS. 8-20 illustrate the construction and function mechanism of thefirst alternative automatic medication delivery device assembly 20according to the invention. With reference to FIGS. 8 to 10, in thisautomatic medication delivery device assembly 20, a pre-filled syringe211, as medication container, can be made of either glass or plasticmaterials. The liquid medication in the pre-filled syringe 211 is sealedby a piston 210 and an elastomeric needle shield 212. The elastomericneedle shield 212 and a needle shield shell 213 is placed at a thedistal end of the syringe 211. A needle shield puller 218 is used toremove the needle shield 212 and the needle shield shell 213 beforeinjection. A dialing cap 201 is used to set the injection dose. A pushcap 202 is used to activate an automatic injection. The push cap 202 isengaged with a dialing cylinder 203. A dose setting area 215 a is beingdefined on a scale cylinder 215. A viewing window 216 a is being definedon a lower cylinder 216. During use, the dialing cap 201 is rotated toset the injection dose. After the dose setting, user removes the dialingcap 201 and exposes the push cap 202. With reference to FIG. 11, usersets the location of a stopping ring 209 along a push rod 206 in orderto get the different injection doses. Meantime, before injection, theautomatic medication delivery device assembly 20 is shown with the pushrod 206 in a locked state, against biasing force of a driving spring208, by a releasable latch mechanism formed between hook feature 206 aon the push rod 206 and the dialing cylinder 203. Before injection, theneedle shield 212 and the needle shield shell 213 are removed and aneedle 211 a is exposed. With reference to FIG. 12, during injection,the push cap 202 is pushed toward to the distal end of the device 20, adistally-directed tapered actuation feature 202 a on the push cap 202releases the releasable latch mechanism formed between hook feature 206a on the push rod 206 and the dialing cylinder 203. The push rod 206 isreleased and the driving spring 208 drives the stopping ring 209together with the push rod 206 to move toward the distal end of thedevice 20. The stopping ring 209 meets the flange feature 211 b on thepre-filled syringe 211. The piston 210 and also the prefilled syringe211 are pushed downward. Consequently, the needle 211 a is inserted into skin and the liquid medication in the pre-filled syringe 211 isinjected from the device into patient's body. FIG. 13 shows theengagement between the dialing cap 201 and the dialing cylinder 203. Ribfeature 201 a on the dialing cap 201 engages with open slot feature 203a on the dialing cylinder 203 when the two components are assembledtogether. When user rotates the dialing cap 201, the dialing cylinder203 rotates accordingly. FIG. 14 shows the engagements among the dialingcylinder 203, the push rod 206 and a lock key 204. The rectangularchannel feature 203 b on the dialing cylinder 203 engages with the flatsurfaces 206 b on the push rod 206. When the dialing cylinder 203 isrotated, the push rod 206 rotates accordingly. The channel feature 203 bfurther provides landing surface for the releasable hook feature 206 aon the push rod 206. Key feature 204 a on the lock key 204 engages intothe slot feature 203 a on the dialing cylinder 203 after the dialing cap201 is removed. At this stage (also shown in FIG. 18), the dialingcylinder cannot be rotated anymore. At the stage shown in FIGS. 13 and17, the rib feature 201 a on the dialing cap 201 pushed down the keyfeature 204 a on the lock key 204 so that the dialing cylinder 203 canbe disengaged from the lock key 204 and rotated along with the dialingcylinder 201. An alternative configuration of dialing cap 201 can beprovided without the rib feature 201 a. In this case, the dialing capstill have the function to protect the push cap 202. However, user willnot be able to use the dialing cap to set the dose. This can be usefulwhen pharmacists or medical professionals prefer to pre-set the dose,using the dialing cap having rib feature 201 a, for patients. Then,pharmacists or medical professionals replace the dialing cap having therib feature 201 a with the dialing cap having no rib feature 201 a. Asthe result, patients will not be able to change the dose after thedevice is dispensed. Furthermore, the match between the rib feature 201a on the dialing cap 201 and the open slot feature 203 a on the dialingcylinder 203 and the key feature 204 a on the lock key 204 can becustomized for different medications and/or different patients, justlike the lock-key match. FIG. 15 shows the engagement between the lockkey 204 and the scale cylinder 215. Leg feature 204 b on the lock key204 engages into slot feature 215 b on the scale cylinder 215 and theleg feature 204 b can move up and down along the slot feature 215 b.FIG. 16 shows the engagement among the push rod 206, the stop ring 209and the pre-filled syringe 211. During the dose setting, user rotatesthe dialing cap 201 and so the dialing cylinder 203 relative to thescale cylinder 215. Because of thread feature 206 c on the push rod 206,when the push rod 206 rotates, the stopping ring 209 moves up and downalong the push rod 206, through the thread engagement between the pushrod 206 and the stopping ring 209. The location of the stopping ring 209can be viewed through the viewing window 215 a on the scale cylinder215. Because of the constrain between groove feature 209 a on thestopping ring 209 and rail feature 215 b on the scale cylinder 215(shown in FIG. 17), the stopping ring 209 can only moves axially, butnot radially along the push rod 206, during dose setting and duringinjection. With reference to FIG. 17, a separation spring 205 is used tosupport the lock key 204. When the dialing cap 201 is assembled with theautomatic medication delivery device 20, the lock key 204 is pushedtoward to the distal end of the device and the separation spring 205 iscompressed. Also shown on FIG. 17, a syringe spring 214 is placedbetween the flange feature 211 b on the pre-filled syringe 211 and aneedle protection sheath 217. During injection, the syringe spring 214is compressed by the push rod 206 and the stopping ring 209. Themovement of the pre-filled syringe, toward to the distal end of thedevice, stops at the landing face feature 216 b on the lower cylinder216. With reference to FIG. 18, after the dialing cap 201 is removed,the separation spring 205 pushes the lock key 204 toward to the proximalend of the automatic medication delivery device 20. The lock key 204restrains the radial movement of the dialing cylinder 205 and the pushrod 206 during injection. Also shown in FIG. 18, an extension sheath 207is used to ensure the rectangular channel 203 b on the dialing cylinder203 always communicate with the feature 206 b on the push rod 206 andrestrain the radial movement of the push rod 206 during the entireinjection. When the push rod 206 moves toward to the distal end of thedevice further enough, the extension sheath 207 is dragged out(telescoping) toward to the distal end of the automatic medicationdelivery device 20, through finger feature 206 d on the push rod 206.FIG. 19 shows the needle protection sheath 217. Flat surface feature 217a on the needle protection sheath 217 is used to support the syringespring 214. Track feature 217 b being defined on the needle protectionsheath 217 is used to control the position of the needle protectionsheath 217. FIG. 20 shows the engagement between the lower cylinder 216and the needle protection sheath 217. A key feature 216 b on the lowercylinder 216 is engaged in the track 217 b on the needle protectionsheath 217. The arrowed dash line shows the movement of the key feature216 b relative to the track 217 b. Before injection, the key feature 216b is at position A.

During injection, the automatic medication delivery device is pushedagainst the skin on user and the key feature 216 b moves to position Brelative to the track 217 b. After injection, when user removes theautomatic medication delivery device 20 away from the skin, the syringespring 214 pushes the needle protection sheath 217 to extend out towardthe distal end of the device 20. The key feature 216 b moves to positionC relative to the track 217 b. The extended portion of the needleprotection sheath 217 covers the needle 211 a after injection. The blockfeature 217 c on the needle protection sheath 217 locks the needleprotection sheath 217 in an extended position.

FIGS. 21-26 illustrate the construction and function mechanism of thesecond alternative automatic medication delivery device assembly 30according to the invention. In this automatic medication delivery deviceassembly 30, the pre-filled syringe 101 is used as medication container.A push cap 304 is used to activate an automatic injection. The push cap304 is engaged with a dialing cylinder 303, through a track 303 a on thedialing cylinder 303. This engagement prevents accidental activation ofthe device before use. A dose setting window 302 a being defined on alower cylinder 302. A scale cylinder 305 has dose scale mark on it.During use, the dialing cylinder 303 is rotated to set the injectiondose. With reference to FIG. 22, user sets the location of the scalecylinder 305 in order to get different injection doses. Meantime, beforeinjection, the automatic medication delivery device assembly 30 is shownwith a push rod 309 in a locked state, against biasing force of adriving spring 308, by a releasable latch mechanism formed between thedialing cylinder 303 and hook feature 309 a on the push rod 309. Thepre-filled syringe 101 is assembled together with the lower cylinder 302through the flange feature 101 b being defined on the pre-filled syringe101. The liquid medication in the pre-filled syringe 101 is sealed by apiston 106 and an elastomeric needle shield 101 a. With reference toFIG. 23, before injection, the needle shield 101 a is removed and theneedle 101 c is exposed. During injection, the push cap 304 is pushedtoward to the distal end of the device 30, a distally-directed taperedactuation feature 304 a on the push cap 304 releases the releasablelatch mechanism formed between the dialing cylinder 303 and hook feature309 a on the push rod 309. The push rod 309 is released and the drivingspring 308 drives the push rod 309 to move toward the distal end of thedevice 30. The piston 106 is pushed downward. A disc feature 309 b onthe push rod 309 stops at the landing feature 305 a on the scalecylinder 305 and the movement of the push rod 309 is limited.Consequently, liquid medication in the pre-filled syringe 101 isinjected into patient's body. FIG. 24 shows the engagements between thepush rod 309 and the dialing cylinder 303. The tongue feature 309 ba onthe disc feature 309 b on the push rod 309 engages with the groovefeature 303 a on the dialing cylinder 303. When user rotates the dialingcylinder 303, the push rod 309 rotates accordingly. FIG. 25 shows theengagements between the push rod 309 and the the scale cylinder 305.During the dose setting, user rotates the dialing cylinder 303 relativeto the lower cylinder 302. Because of the engagement between the pushrod 309 and the dialing cylinder 303, the rotation of dialing cylinder303 cause the rotation of the push rod 309. When the push rod 309rotates, the scale cylinder 305 rotates accordingly because of theengagement between the rectangular channel 305 b on the scale cylinder305 and the flat engagement surface 309 c on the push rod 309. Thethread feature 305 c on the scale cylinder 305 engages with the threadkey feature 302 a on the lower cylinder 302. When the scale cylinder 305rotates, the scale cylinder 305 also moves up and down along the axialof the push rod 309, through the thread engagement between the scalecylinder 305 and the lower cylinder 302. The location of the scalecylinder 305 can be viewed through the viewing window 202 a on the lowercylinder 302. The dose mark feature 305 d on the scale cylinder 305 canbe used for dose indication. FIG. 26 shows the engagements among thedialing cylinder 303, the scale cylinder 306 and the lower cylinder 302.In operation steps other than the dose setting step, the dialingcylinder 303 is always locked with the lower cylinder 302 together,through the tooth engagement between 303 c on the dialing cylinder 303and 302 c on the lower cylinder 302. During the dose setting step, userpushes down the dialing cylinder 303 relatively to the lower cylinder302. Then, the tooth-type locking engagement between 303 c and 302 c isdisabled and the dialing cylinder 303 can be rotated relatively to thelower cylinder 302.

After the dose setting, when there is absent of pushing down force, thedialing cylinder 303 is pushed up and re-engaged with the scale cylinder302, due to the resilient force generated by the resilient fingerfeature 302 b on the lower cylinder 302. The upward movement of thedialing cylinder 303 is stopped by the flange feature 303 b on thedialing cylinder 303 and the hook feature 302 d on the lower cylinder302.

FIGS. 27-28 illustrate the construction and function mechanism of thethird alternative automatic medication delivery device assembly 40according to the invention. The dose setting mechanism and activationmechanism of the automatic medication delivery device 40 is the same asthose of the automatic medication delivery device 30. In this automaticmedication delivery device assembly 40, a pre-filled cartridge 404 isused as medication container. The pre-filled cartridge 404 is assembledtogether with a lower cylinder 403 through a cartridge sheath 402. Theproximal end of the cartridge sheath has the slot feature 402 a, whichis used to engage with the snap figure feature 403 a on the lowercylinder 403. The distal end of the cartridge sheath 402 has the threadfeature 402 b, which is used to engage a double-ended pen needle 401.

FIGS. 29-34A illustrate the construction and function mechanism of thefourth alternative automatic medication delivery device assembly 50according to the invention. The dose setting mechanism and activationmechanism of the automatic medication delivery device 50 is the same asthose of the automatic medication delivery device 30. In this automaticmedication delivery device assembly 50, the pre-filled syringe 211 isused as medication container. Furthermore, an automatic needle insertionmechanism is introduced in the automatic medication delivery deviceassembly 50. A syringe housing 502 is used, together with a lowercylinder 503, to host the pre-filled syringe 211. A needle shield puller501 is used to remove the needle shield 212 and the needle shield shell213 before injection. FIG. 30 shows the syringe housing 502. There areone-way, bendable, positioning fingers 502 a being defined on thesyringe housing 502. The length of the positioning fingers 502 a is morethan the length that required to disengage the needle shied 212 from thesyringe 211. The proximal end 502 aa of the positioning FIGS. 502a isused to support the flange feature 211 b on the pre-filled syringe 211,before injection. FIG. 31 shows the automatic medication delivery device50 with different dose setting before injection. Before injection, theflange feature 211 b on the pre-filled syringe 211 is rested at theproximal end 502 aa of the positioning fingers 502 a. To further supportthe pre-filled syringe 211 to be placed at the proximal end 502 aabefore injection, an optional supporting spring (not show) can be placedbetween the syringe flange 211 b and surface 502 c on the syringehousing 502. In the case that the syringe 211 moves a short distancedistally during the needle shield removal, the supporting spring willpush the syringe 211 to move back to the proximal end 502 aa. Meantime,the counter force generated by the optional supporting spring is lessthan the force generated by a driving spring 508 so that the distaltoward movement of the syringe 211 won't be impeded by the optionalsupport spring. FIG. 32 shows the automatic medication delivery device50 with different dose setting after injection. It can be seen thatduring injection, the flange feature 211 b on the pre-filled syringe 211is placed at the distal end 502 ab of the positioning fingers 502 a whena driving spring 508 pushes the piston 210 and the pre-filled syringe211 toward to the distal end of the automatic medication delivery device50. Because the barrel of the pre-filled syringe 211 won't contactinjection site during the injection, there is no resistance for theflange feature 211 b to move to the distal end 502 ab of the positioningfingers 502 a. FIG. 33 shows syringe housing 512, as an alternative tosyringe housing 502. The syringe housing 512 has lock key feature 512 aand finger feature 512 b. The syringe housing 512 engages with aprotection ring 513. Before injection, shown as FIG. 34, the axialmovement of the protection ring 513 is blocked by the lock key feature512 a on the syringe housing 512, and the support finger feature 513 aon the protection 513 prevents the syringe 211 to move distally. Whenuser is ready for injection, user rotates the protection ring 513 torelease position. At the release position, the protection ring can movedistally. As shown in FIG. 34A, after injection, both the syringe 211and the protection ring 513 to move distally, and the position ofsyringe 211 is stationed by the finger feature 512 b.

FIGS. 35-39 illustrate the construction and function mechanism of thefifth alternative automatic medication delivery device assembly 60according to the invention. In this exemplary automatic medicationdelivery device assembly 60, a syringe 601, as medication container, canbe made of either glass or plastic materials. A needle shield (or needlecap) 601 a is placed at a the distal end of the syringe 601. A pushbutton 603 is used to activate an automatic injection. The push button603 is engaged with a connector 602. With reference to FIG. 36, userfirst removes the needle shield 601 a. Then, user pulls a push rod 604proximally and draws medication into the syringe 601 from vial 650. Withreference to FIGS. 37 to 37C, the connector 602 is assembled withsyringe 601 through a flange feature 601 b on the syringe 601. Beforeinjection, a driving spring 605 is in extended stage and a piston 606 islocated at the distal end of the automatic medication delivery device60. To draw medication into the syringe 601, user pulls the push rod604, through the finger flange feature 604 a on the push rod 604, towardto the proximal end of the automatic medication delivery device 60. Thepiston 606 is moved toward to the proximal end of the automaticmedication delivery device 60 accordingly. Blocking feature 602 a on theconnector 602 engages with a series of teeth feature 604 b on the pushrod 604 in order to block the movement of the push rod 604 toward distalend of the device 60, which is driven by the driving spring 605. Theteeth feature 604 a on the push rod 604 is used to set differentinjection doses. A dose marking can be placed on the push rod 604 forassisting the dose setting. During injection, the push button 603 ispushed inward to the push rod 604, and the blocking feature 602 a on theconnector 602 is pushed outward from the push rod 604 accordingly (shownin FIG. 37B). The engagement between blocking feature 602 a and theteeth feature 604 b is disabled. Then, the push rod 604 is released andthe driving spring 605 drives the the push rod 604 to move toward thedistal end of the device 60. The piston 606 is pushed downward.Consequently, liquid medication in the syringe 601 is injected intopatient's body. FIGS. 38 and 39 show the engagements among the push rod604, the connector 602 and the push button 603. Before injection, theteeth feature 604 b on the push rod 604 is engaged with the blockingfeature 602 a on the connector 602. A bendable finger feature 602 b onthe connector 602 biases the push button 603 outward relative to thepush rod 604. As shown in FIG. 39, during injection, user pushes thepush button 603 toward to the push rod 604. A flat feature 603 a on thepush button 603 pushes the blocking feature 602 a on the connector 602outward in order to release the push rod 604 for injection.

FIGS. 40 and 41 illustrate the construction and function mechanism ofthe sixth alternative automatic medication delivery device assembly 70according to the invention. The dose setting mechanism and activationmechanism of the automatic medication delivery device 70 is the same asthose of the automatic medication delivery device 60. In this automaticmedication delivery device assembly 70, a luer-lock syringe 701 is usedas medication container. The luer-lock syringe 701 is assembled togetherwith the connector 602. The distal end of the luer-lock syringe connectsto a luer-lock needle 702.

FIGS. 42-45 illustrate the construction and function mechanism of theseventh alternative automatic medication delivery device assembly 80according to the invention. The activation mechanism of the automaticmedication delivery device 80 is the same as those of the automaticmedication delivery device 60. In this automatic medication deliverydevice assembly 80, the pre-filled syringe 211 is used as medicationcontainer. A housing 803 is used to host the pre-filled syringe 211. Acap 807 is placed at the proximal end of the housing 803. A dose settingring 805 is introduced to set the different injection dose. As shown inFIG. 42, before injection, user moves the dose setting ring 805 alongthe dose setting area 803 a on the housing 803. A needle shield puller804 is used to remove the needle shield 212 and the needle shield shell213 before injection. As shown in FIG. 43-45, during injection, userpushes the push button 603 inward. The lock mechanism between the pushrod 806 and a connector 802 is released. A driving spring 809 drives thepush rod 806 move toward the distal end of the automatic medicationdelivery device 80. The movement of the push rod 806 stops when theflange feature 806 a on the push rod 806 meets the dose setting ring805. Rib feature 806 aa on flange feature 806 a engages with teethfeature 805 a on the setting ring 805 to prevent further rotationalmovement of the dose setting ring 805. Different injection doses areachieved by placing the dose setting ring 805 at the differentpositions. Furthermore, an automatic needle insertion mechanism isintroduced for device 80. A driving spring 809 pushes the push rod 806and the piston 210 and the pre-filled syringe 211 toward to the distalend of the automatic medication delivery device 80. A syringe supportspring 808 is compressed. A bendable finger feature (hidden in thecross-sectional views), as the same as the one shown in automaticmedication delivery device 50, is used to lock the pre-filled syringe211 in place after the syringe support spring 808 is compressed.Alternatively, design mechanism shown in FIGS. 33-34A can be implementedfor the device 80.

FIGS. 46 and 47 illustrate an alternative configuration of the seventhalternative automatic medication delivery device assembly 80 accordingto the invention. In this alternative configuration, the dose settingring 805 is place more proximally than the flange feature 806 a on thepush rod 806. In this way, the dose setting ring 805 is used to pre-setthe maximum dose of injection.

FIG. 48 illustrates that the dose setting ring 805 engages with thehousing 803 through thread feature 803 b on the housing 803.

FIGS. 49 and 50 illustrates the construction and function mechanism ofthe eighth alternative automatic medication delivery device assembly 90according to the invention. The dose setting mechanism and activationmechanism of the automatic medication delivery device 90 is the same asthose of the automatic medication delivery device 80. In this automaticmedication delivery device 90, instead of the needle shield 212 and theneedle shield shell 213, a compressible needle shield sub-assembly 904is used. A housing 903 is introduced to host the compressible needleshield sub-assembly 904. The compressible needle shield sub-assembly 904is formed by a compressible component 904 a, a rigid needle shield frame904 b and an elastomeric needle shield 904 c. During injection, theautomatic medication delivery device assembly 90 is pushed againstpatient's skin at the injection site. The compressible component 904 acollapses. The needle 211 a pierces the elastomeric needle shield 904 cand is inserted into skin for injection. This design allows user to skipthe mannual needle shield removal step before injection. This designalso allows pre-set vacuum inside the syringe barrel 211.

FIGS. 51-55 illustrate the construction and function mechanism of theninth alternative automatic medication delivery device assembly 100according to the invention. In this exemplary automatic medicationdelivery device assembly 100, a syringe 601, as medication container,can be made of either glass or plastic materials. A push button 1002 isused to activate an automatic injection. The push button 1002 is engagedwith a connector 1001. The connector 1001 is covered by a covercomponent 1004. With reference to FIG. 53-53B, user first removes theneedle shield 601 a. Then, user pulls the flange feature 1003 a on apush rod 1003 toward to proximal end of the automatic medicationdelivery device 100 and draws medication into the syringe 601. When thepush rod 1003 is pulled toward to the proximal end of the automaticmedication delivery device 100, the teeth feature 1003 b engages withthe gear feature 1005 a on the driving gear 1005 and causes the rotationof the driving gear 1005. The rotation of the driving gear 1005generates tension torque on a torsion spring 1006. With reference toFIGS. 53 to 53B, the connector 1001 is assembled with syringe 601through a flange feature 601 b on the syringe 601. Before injection, thetorsion spring 1006 (hidden in FIGS. 51 to 51B) is in relaxed stage anda piston 606 is located at the distal end of the automatic medicationdelivery device 100. When drawing medication into the syringe 601, thepiston 606 is moved toward to the proximal end of the automaticmedication delivery device 100 accordingly. Meantime, the torsion spring1006 is wound up. The blocking feature 1001 a on the connector 1001engages with a ratchet feature 1005 b on the driving gear 1005 in orderto block the movement of the push rod 1003 toward the distal end of theautomatic medication delivery device 100, driven by the torsion spring1006. The teeth feature 1003 a on the push rod 1003 is used to setdifferent injection doses. During injection, the push button 1002 ispushed toward to the distal end of the automatic medication deliverydevice 100. Through a chamfer feature 1002 a on the push button 1002,the blocking feature 1001 a on the connector 1001 is pushed away fromthe ratchet feature 1005 b on the driving gear accordingly, and the pushrod 1003 is released. The engagement details between blocking feature1001 a and the ratchet feature 1005 b are shown in FIGS. 54 and 55. Whenthe push rod 1003 is released and the torsion spring 1006, through thedriving gear 1005, drives the the push rod 1003 to move toward thedistal end of the device 100. The piston 606 is pushed downward.Consequently, liquid medication in the syringe 601 is injected intopatient's body.

FIGS. 56-59 illustrate the construction and function mechanism of thetenth alternative automatic medication delivery device assembly 110according to the invention. The activation mechanism of the automaticmedication delivery device 110 is the same as those of the automaticmedication delivery device 100. In this automatic medication deliverydevice assembly 110, the pre-filled syringe 211 is used as medicationcontainer. A housing 1108 is used to host the pre-filled syringe 211. Acover 1104 is assembled with a connector 1101. A dose setting tab 1107is introduced to set the different injection dose. Before injection,user moves the dose setting tab 1107 along the dose setting area 1104 aon the cover 1104. FIGS. 56 and 57 show that the dose setting tap 1107is placed at different location for different injection doses. A needleshield puller 1106 is used to remove the needle shield 212 and theneedle shield shell 213 before injection. During injection, user pushesthe push button 1002 to activate the automatic medication deliverydevice 110. The lock mechanism between a push rod 1103 and the connector1101 is released. The torsion spring 1006 (hidden) drives the drivinggear 1005 to rotate. The rotation of the driving gear 1005 causes thepush rod 1103 move toward to the distal end of the automatic medicationdelivery device 110, through the teeth feature 1103 a on the push rod1103. The movement of the push rod 1103 stops when the flange feature1103 b on the push rod 1103 meets the dose setting tab 1007 (shown inFIG. 59). Different injection doses are achieved by placing the dosesetting tab 1107 at the different positions. Furthermore, an automaticneedle insertion mechanism is introduced. The torsion spring 1006 pushesthe push rod 1103 and the piston 210 and the pre-filled syringe 211toward the distal end of the automatic medication delivery device 110. Asyringe support spring 1109 is compressed. A bendable finger feature(hidden in the cross-sectional views), as the same as the one shown inautomatic medication delivery device 50, is used to lock the pre-filledsyringe 211 in place after the syringe support spring 1109 iscompressed. Alternatively, design mechanism shown in FIGS. 33-34A can beimplemented for the device 80.

FIGS. 60 illustrates an alternative configuration of the tenthalternative automatic medication delivery device assembly 110 accordingto the invention. In this alternative configuration, the dose settingtab 1107 is placed more proximally than the flange feature 1103 b on thepush rod 1103. In this way, the dose setting tab 1107 is used to pre-setthe maximum dose of injection.

In the above embodiments, the dose setting is bidirectional for theautomatic medication delivery devices 10, 20, 30, 40, 50, 80 and 110.

All the features in the above embodiments and design concepts herein canbe inter-changed and combined to generate new device designs. Those ofskill in the art will understand that modifications (additions and/orremovals) of various components of the apparatuses, methods and/orsystems and embodiments described herein may be made without departingfrom the full scope and spirit of the present invention, which encompasssuch modifications and any and all equivalents thereof.

1: A medication delivery device, for use with a container having adistal end and a needle being placed at said distal end of saidcontainer, comprising: a push rod which is movable with respect to atleast a portion of said container; a resilient member configured to biassaid push rod to move toward said distal end of said container; areleasable restraining means configured to releasably restrain said pushrod in a locked state against said biasing of said resilient member,wherein, upon release of said releasable restraining means, said pushrod moves under force of said resilient member toward said distal end ofsaid container; a means to adjust amount of movement of said push rodwith respect to said container in order to deliver a predetermined doseof medication, upon release of said releasable restraining means; and anactivation means configured to release said releasable means. 2: Amedication delivery device as in claim 1, wherein said means to adjustamount of movement of said push rod with respect to said container isbidirectional. 3: A medication delivery device as in claim 1 furthercomprising a means to prevent said predetermined dose of medication frombeing changed. 4: A medication delivery device as in claim 1, whereinsaid means to adjust amount of movement of said push rod with respect tosaid container is differentiable for different medications. 5: Amedication delivery device as in claim 1 further comprising a means toprevent over dosing. 6: An automatic injection device as in claim 1further comprising an automatic needle insertion means configured toautomatically insert said needle into medication injection site. 7: Amedication delivery device as in claim 1 further comprising a means tomove said container distally. 8: A medication delivery device as inclaim 1 further comprising a means to prevent accidental activation ofsaid medication delivery device. 9: A medication delivery device as inclaim 1 further comprising a needle shield to cover said needle beforeinjection. 10: A medication delivery device as in claim 9 wherein saidneedle shield being pierced by said needle during medication injection.11: A medication delivery device as in claim 1 further comprising ameans to at least partially cover said needle after said predetermineddose of medication is delivered.